1. Field of the Invention
The present invention relates to an image reading device, an image forming apparatus, a method for controlling image reading, and a non-transitory computer-readable medium.
2. Description of the Related Art
An image reading device has been known that mounts a document on a contact glass, moves a carriage below the contact glass, and thereby reads an image from the document.
Japanese Unexamined Patent Application No. 2010-118819 discloses such an image reading device that, in order to read a document at high speed, reads images from a document at half resolution in positions displaced in a sub-scanning direction by one line each in an outgoing path and a return path in the sub-scanning direction, combines the images for each line, and thereby obtains image data of the document.
However, the image reading device disclosed in Japanese Unexamined Patent Application No. 2010-118819 must perform reading while displacing a reading line in the outgoing path and a reading line in the return path precisely and has a problem in that when unexpected deviation occurs, image quality degrades when the images of the outgoing path and the return path are combined with each other.